species identical with species existing in our shallow seas find an existence there. That we should have fallen into such errors, and induction, deduction, and ratiocination (to use the Mill terminology), be found in fault, is not surprising, for astronomers, whose observations and calculations are more within the range of "verification," are waiting for the transit of Venus, to ascertain whether or not an error of four millions of miles (a small fraction indeed of the whole distance) has been made in the calculation of the earth's distance from the sun. The discovery of the remains of pre-historic man under certain circumstances in Western Europe is adduced as proof of his great antiquity, and the revival of the Lamarckian theory, the descent of man from the ape, throws back our origin to a very remote period. Some geologists of

the first order affirm, some equally eminent deny, that the operations and forces of Nature have been the same, and of the same magnitude and intensity, from the earliest dawn of creation to our own epoch, and any numbers of thousands of years, heavy "drafts on the bank of time," as Sir C. Lyell calls them, are assumed to be the time required for the accumulations of certain deposits, deltas of rivers, gravel-beds, and the erosion of valleys and gorges. To the consideration of such theories and conjectures the following pages are devoted, in an earnest desire for the elucidation of truth, the object of true science. It must, however, be observed that, inasmuch as some of the theories referred to, and to be considered, are founded upon deductions derived for the most part from conjectures with a minimum of fact to support them, and,

from the nature of the case, incapable of verification, the argument must necessarily, in various instances, be confined to showing that the probabilities are as great on one side of the question as the other. The discoveries of Dr. Carpenter show the necessity of not blindly concurring in scientific or so-called scientific conclusions, however eminent the authority which has promulgated them. The views of geologists of the greatest eminencethe loss of one of whom, the late Sir R. Murchison, all geologists must deplore-are so antagonistic on some material points, that the uncertainty of the vera causa of certain geological phenomena, unfortunately incapable of actual proof, is rendered still more uncertain. It will therefore, it is hoped,

be considered a legitimate occupation, where "doctors differ," to inquire into the subject

matter of their difference, as well as to consider arguments as liable to error as

those which the deep-sea soundings have detected.